A significant portion of antibiotic-allergic patients are sensitive to multiple antibiotics

Researchers from Penn State Hershey Medical Center in Hershey, Pennsylvania, used a retrospective chart review to characterize features of multiple antibiotic allergies in both pediatric and adult populations.

With appropriate approval and using electronic medical records, they identified 7060 antibiotic-allergic patients with self-reported or physician-diagnosed antibiotic allergy.

Multiple antibiotic allergies to two or more different drug classes were reported in 1106 (15.7%) of patients. Of these, 78.5% reported allergy to two antibiotic classes, 14.5% to three classes, 5% to four classes, 1.4% to five classes, 0.4% to six classes, and 0.3% to seven or more classes. The frequency of multiple antibiotic allergies varied by gender according to age, with a female:male ratio of 1.3 in pediatric patients and 4.3 in patients over 20 years of age.

According to the researchers, the numbers of patients with multiple allergies increased with age in both genders, with the greatest number seen in ages 50 to 69. Sixty-five percent of all multiple antibiotic allergies were sulfa drugs, 39.3% macrolides, 38.9% penicillins, 33.0% quinolones, 17.2% cephalosporins, and 16.4% tetracyclines.

“A significant portion of antibiotic-allergic patients have sensitivity to multiple antibiotics,” the researchers concluded, noting “There is a strong female predominance among multiple antibiotic-allergic adult patients, but not pediatric patients.”